Cooler



FIG. 1 is a top front right side perspective view of a cooler showing our new design;

FIG. 2 is a front side view thereof;

FIG. 3 is a right side view thereof (the left side is a mirror image of FIG. 3); and,

FIG. 4 is a top plan view thereof. 

The ornamental design for a cooler, as shown and described. 